Drill tool joint



Sept. 27, 1932.

5.1 EEEEEEE ON 7 1,879,856 1 ILL 00L JOINT Patented Sept. 27, 1932 1mm 1.. rE'rEasoN, or WOOSTEB, onio DRILL moon 301m Application filed March 25, 1929. Serial no, 349,870.

My invention relates to improvements in tooljoints for use in drilling oil, gas, and

artesian wells. Its principal object is to provide improved means for connecting the 'male and female members of the oint whereby added strength is given to the parts,

' especially to the male member to prevent heretofore.

breakage thereof when subjected .to the great strain in tightening'the coupling, and wear and tear of the joint during the drilling process, without the use of a collar as employed For, as is well known, there is a tremendous lifting and twist strain upon that,,upon severe a tool joint of this character set up when the'bit is coupled by means of massive and powerful wrench tools used for the urpose and this strain, together with the ad ed stress and shock upon thejoint when the bit strikes Y the solid rock requires improved means for the prevention of breakage at this joint.

Continued experiment has demonstrated strain, the tapered threaded male member of the joint is apt to break off at the font made for the last thread therein at I its inner end, and that at this point the strain is excessively great because of the natural pressure'and leverage there in the connection a with the shoulder of the female member, causing a tendency to break at the bottom "of the last thread because it bears all the stress at that point, and the strain isnot distributed beyond it; but is centeredthere, and

to overcome this defect, I have providedmeans-t'o distribute the breaking -strain which was previously localized at thelast turn of the thread, along an extended portion of the male member or extension, said means comprising a zone of substantial width between the shoulder at the inner end ofsaid extension and the s'crewthread, saidizone being of My invention is illustrated inone specific embodiment, by the accompanying drawing 7 in which similar letters and figures of referenceindieate like parts- -Referring thereto, Fig. 1 is a sidejelev ation of the male member of the tooljoint; I Fig. 2 is a side view of the two members of thetool joint, united together, and parts cut away to exhibit the interior. l

, In the figure, A is the male member and B, the female member of the joint; G indicates the tapered threaded end of thepart A, which intermeshe's with the corresponding threaded cavity, D inthe usual well known way.- E indicates. the cylindrical neck or extension of the tapered part (J-beyond the last'thread shown by the dotted line 0, and -clrindicates the cavity extenson into the end of the body portion of the male part A, which terminates with a shoulder at a, abutting a ainst the terminus b of the female part B. fire body portions of thepair of, joint members are-squared in the usual manner tov fa cilitate screwing the parts together by wrench tools, and the device is particul'arlyapplicable to solidly connect the drill pin of an ordinary drill .tool of'a derrick to the cable end thereof,;and is quite simple in construc tion,andinexpensivqas well as s'tronger than I .dr-illj oints. heretofore employed.

Y In-applicants joint the incision of the thread,-whe re breakage usually occurs, is'not pointfis overcome largely by the neck c'ontaken up in shear -alone.. In other'words, when thelateral forces areapplied to applicants joint the stress is largely taken up in bending 'or yielding resiliently in the neck, due to the fact that it is out ofcontact with the socket its entire length, while in the .old

15 eliminated, butthe tendency,to'break'a't this ,structionwhereby the shock" and stress is taken up by the yielding in the neck as against .the old construction in which the stress is construction, where the pin isi'n tight en- 'gagement with the socket thruout its length, 1

the stress is entirely taken up in the shear of thefinal'threa'd, and for this reason the bit 7 a diameter no greater than that ofthe valley of-the last turn of the thread.

the stem of the male'member tends to lessen its rigidity, and thus-contributes somewhat to its flexibility and its capacity. to sustain plain perip e this 7th day of February,

the shock given to the tool joint when operating upon hard substances.

Attention is invited to the fact that the recess or groove G around the inner end of the peripherally-plain neck E, allows said neck to have greater length and hence greater yieldability than could otherwise be produced without removing one or more convolutions of the screw thread from the portion C and consequently weakening the threaded joint. Then too, the groove G located between the neck E and the periphery of the tool section A, separates the shoulder a from said neck and hence renders said shoulder more acces sible for grinding and polishing with a stone. It has heretofore been customary to keep the abutting shoulders of the tool sections A and B ground and polished to obtain accurate contact between them, and the required operations in connection with the tool section A, are expedited in the present joint, due to the greater accessibility of the shoulder a. The plain periphery of the neck E forms the inner wall of the groove G and said periphery preferably joins the groove bottom by means of a fillet F to prevent the existence of a sha corner which would constitute a possible line of fracture.

I claim:

In a well drill coupling member, a cylindrical body having a reduced integral extension at one end, a continuous end-facing groove surrounding theinner end of said extension and a continuous end-facing integral shoulder from the outer wall of said groove to the periphery of said body, said extension having a relatively short peripherally-plain neck portion whose plain periphery forms the inner wall of said groove and merges into the groove bottom by means of a fillet, said extension being tapered from said neck portion to its outer end and having a screw thread which projects beyond the plain periphery of said neck portion, the valleyof said thread terminatin substantially flush with said of said neck portion. In witness w ereof, I hereunto set my hand BERT L. PETERSON r 

